NEW YORK — Office Depot and OfficeMax have agreed to merge in an all-stock deal that would transform the $21.2 billion office supply retail sector. Boca Raton, Fla.-based Office Depot and Naperville, Ill.-based OfficeMax say holders of OfficeMax shares will receive 2.69 shares of Office Depot for every OfficeMax share they own. That’s equal to about $13.50 per share, giving the deal a total value of about $1.2 billion. Analyst say if the deal closes it would likely benefit the largest office supply player Staples because the combined entity will likely close stores.